Equine Cushing’s disease has had a variety of labels over the years, with PPID (‘Equine pituitary pars intermedia dysfunction’) currently being the most accepted name in the veterinary community. For the sake of simplicity however, and for my own sanity (having always known it this way!), I will refer to it as Cushings.

Although I have always had a general awareness of Cushings, it was only after reading an article on how the disease appears to be on the increase in today’s horses that I was prompted to wonder why.

Whilst it used to be thought that the cause of the disease was due to a benign tumour of the pituitary gland, it is now believed that Cushings is caused by a degeneration of dopamine producing neurons in the hypothalamus. In its advanced form, Cushings is relatively easy to diagnose due to the presence of classic clinical signs. The difficulty though lies in identifying Cushings early on in a bid to slow down the degenerative process.

Horses with early Cushings have a history of decreased muscle mass, loss of condition, reduced performance and development of abnormal fat deposits. With more awareness on key signs however, early onset Cushings is becoming easier to diagnose and treat.

As I’ve been seeing more and more cranial compression in the horses I treat, I’ve begun to wonder if such compression could be part of the cause of Cushings. A horse’s skull is exposed to more pressures than any other part of the body and on a regular basis. These pressures come from a variety of sources: bits, bridles, nosebands, invasive procedures on the head such as dental work and trauma. This creates effects on the individual bones of the skull, surrounding soft tissue, muscles and the cranial nerves. It’s already been shown how compression is a key cause of headshaking and I’ve been wondering if when the glands involved in producing the hormones involved in Cushings, namely the pituitary and hypothalamus glands, are crushed due to some form of compression, they may be being prevented from functioning in the normal way.

Existing clients with Cushings have always presented with some form of cranial compression but I was interested to see if there was a common theme in horses that had never had craniosacral therapy. After sessions with five horses and ponies whom I’d never met, I found that each one presented with frontal bone compression. A trauma to this bone would cause a shunt backwards, invading the area surrounding the pituitary and hypothalamus glands.

Obviously not all horses get Cushings so it’s not to say there isn’t more to it such as diet but, if a horse is already set up to get Cushings, could the condition be worsened due to a compression to the cranium hindering performance of the glands involved? If this is the case, could it be possible that by releasing the glands and freeing them up could give them a chance to start to function how they should, albeit at a fraction of their ability and ease some of the symptoms hindering Cushings horses? Either way, it’s important to consider the horse’s head in all aspects of its daily life. With it being exposed to so much, ignoring it means ignoring the potential for our horses to lead more comfortable lives.